Carebene and isocyanide ligation at ruthenium(II) with (η 6-arene) and tethered phosphinopropylarene ligands

Article abstract of DOI:10.1016/S0020-1693(02)01492-5

Reactions of [(η⁶-1,2,4,5-Me₄C₆H ₂)Ru(DPVP)Cl₂] (DPVP=diphenylvinyl phosphine), with (trimethylsilyl)acetylene and phenylacetylene in the presence of NaPF ₆ in methanol gave the (methoxy)-a

Full text of DOI:10.1016/S0020-1693(02)01492-5

Inorganica Chimica Acta 350 (2003) 12ꢁ24
/
www.elsevier.com/locate/ica
Carebene and isocyanide ligation at ruthenium(II) with (h6-arene)
and tethered phosphinopropylarene ligands
Kesete Y. Ghebreyessus, John H. Nelson *
Department of Chemistry/216, University of Nevada-Reno, Reno, NV 89557-0020, USA
Received 4 February 2002; accepted 22 April 2002
Dedicated to Professor Pierre Braunstein.
Abstract
Reactions of [(h6-1,2,4,5-Me4C6H2)Ru(DPVP)Cl2] (DPVPꢀ
phenylacetylene in the presence of NaPF6 in methanol gave the (methoxy)ꢁ
(OMe)(R))(DPVP)(Cl)]PF6 (Rꢀ
CH3, 1a; CH2Ph, 2a). Similarly, treatment of [(h6-1,2,4-Me3C6H2ꢁ
(C6H5)2)RuCl2] with (trimethylsilyl)acetylene, phenylacetylene and 1,1-diphenylpropargyl alcohol in the presence of NaPF6 gave
the tethered carbene complexes [(h6-1,2,4-Me3C6H2ꢁ
5-CH2CH2CH2P(C6H5)2)Ru(ꢀC(OMe)(R))(Cl)]PF6 (RꢀCH3, 1b; CH2Ph, 2b;
CHꢀCꢁ CH2CH2CH2P(C6H5)2)RuCl2] are shown
Ph2, 3b), respectively. The complexes, [(h6-arene)Ru(DPVP)Cl2] and [(h6-areneꢁ
to be useful catalyst precursors for the hydration of phenylacetylene to afford acetophenone. The complexes, [(h6-arene)R-
u(DPVP)Cl2] (areneꢀ1,3,5-Me3C6H3 1, p-MeC6H4CHMe2 2, 1,2,4,5-Me4C6H2 3 and Me6C6 4) react with excess phenyl-isocyanide
4c. The related tethered complexes 1d and
/
diphenylvinyl phosphine), with (trimethylsilyl)acetylene and
alkylcarbene complexes [(h6-1,2,4,5-Me4C6H2)Ru(ꢀ
5-CH2CH2CH2P-
/
/C
/
/
/
/
/
/
/
/
/
and NaPF6 in methanol to produce [(h6-arene)Ru(DPVP)(CNPh)(Cl)]PF6 derivatives 1cꢁ
/
2d were prepared from [(h6-arene-CH2CH2CH2P(C6H5)2)RuCl2] by using the same methodology. All the complexes have been
characterized spectroscopically and the crystal structures of some of them have been obtained.
# 2002 Elsevier Science B.V. All rights reserved.
Keywords: Areneꢁruthenium; Carbene; Isocyanide complexes; Catalysis
/
1. Introduction
Isocyanides, compared with isoelectronic phosphines
are less commonly encountered as auxiliary ligands [4];
they are weaker electron donors than phosphines [5].
When coordinated to a metal site with a higher
oxidation state, isocyanides can be activated towards
nucleophilic attack [6] (Eq (1)).
The reaction of terminal alkynes and propargyl
alcohols with (h6-arene)ruthenium(II) complexes is
now reasonably well-established [1]. It represents a
simple and convenient route for the preparation of
Fisher type alkoxy carbenes via reactive vinylidene and
allenylidene intermediates. Notably, remarkable devel-
opments in the catalytic application of vinylidenes to
promote selective Cꢁ
/
C bond forming reactions [2] and
allenylidenes in the ring-closing metathesis of olefins
have been reported [3]. The first part of this report
describes the synthesis and characterization of (meth-
ð1Þ
Nucleophilic attack occurs at the ligated C-atom to
give aminocarbene complexes. This type of reactivity
was shown to be facilitated when the isocyanide ligand is
coordinated to an electron-poor metal center [6,7].
Several reviews of various aspects of these types of
synthesis have been published [6]; with palladium(II)
and platinum(II) being among the most widely used
oxy)ꢁ
/
alkyl and (methoxy)ꢁalkenylcarbene complexes
/
derived from (h6-arene) and tethered [(h6-areneꢁ
(CH2CH2CH2P(C6H5)2] ruthenium(II) precursors.
/
* Corresponding author.
E-mail address: jhnelson@unr.edu (J.H. Nelson).
0020-1693/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
doi:10.1016/S0020-1693(02)01492-5

K.Y. Ghebreyessus, J.H. Nelson / Inorganica Chimica Acta 350 (2003) 12ꢁ
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13
1
transition metal centers. To our knowledge, there are
only a few reported isocyanide (h6-arene)ruthenium(II)
complexes [4b,8] and far fewer aminocarbenes derived
therefrom. The aim of the second part of this paper is to
synthesize (h6-arene)ruthenium(II) phenyl-isocyanide
complexes and to investigate the preparation of amino-
carbene complexes from them.
a chiral ruthenium center, the H NMR spectra of 2a
and 2b show AX spin systems consisting of resonances
at 5.05 and 3.78 ppm for 2a and 4.81 and 4.17 ppm for
2b (2J(HH)ꢀ
topic benzylic protons. The areneꢁ
and 1b are also chemical shift inequivalent. Further-
/
12.5 Hz), respectively, for the diastereo-
/methyl groups in 1a
1
more, the H NMR spectra of 1b and 2b display three
multiplets in the aliphatic region corresponding to the
three sets of methylene protons. In their 13C NMR
spectra, the typical lowfield doublet (327ꢁ
coupled with the 31P nucleus of the phosphorus ligand
(2J(PC)ꢀ
19.0 Hz) supports the existence of the RuꢀCa
carbene moiety. The RuꢀCa carbon resonance for 1b
/
322 ppm)
2. Results and discussion
/
/
2.1. Synthesis of (methoxy)ꢁ
and 2b)
/
alkylcarbenes (1a, 2a, 1b
/
was not detected in the 13C{1H} NMR spectrum. In
their 31P{1H} NMR spectra, the complexes show a
singlet at d 30.70 1a, 31.0 2a, 29.89 1b, 27.71 2b,
respectively, corresponding to the coordinated DPVP.
Low-temperature spectra of 1a and 1b showed no
Treatment of a methanolꢁdichloromethane solution
/
of [(h6-1,2,4,5-Me4C6H2)Ru (DPVP)Cl2] with excess
(trimethylsilyl)acetylene in the presence of 1 equiv. of
NaPF6 resulted in the formation of the (methoxy)ꢁ
methylcarbene ruthenium(II) complex 1a (Scheme 1).
Similarly, the (methoxy)ꢁbenzylcarbene complex 2a
/
splitting of any resonance upon lowering the tempera-
1
ture to ꢂ
/
90 8C and H NOE experiments also showed
/
that all the complexes are dynamic. This leads us to
conclude that the carbene ligand is freely rotating about
was synthesized from an excess of phenylacetylene
(Scheme 1). Analogous carbene complexes 1b and 2b
were also synthesized by treating the tethered [(h6-1,2,4-
the Ruꢁ/C bond [9].
X-ray crystal structures of 1a, 1b and 2b were
determined. Crystallographic data are given in Table
1. Selected bond angles and distances are given in Table
2. Views of the molecular structures of 1a and 1b are
shown in Figs. 1 and 2, respectively. The ruthenium
center in each of these complexes possesses a pseudo-
octahedral geometry. For 1a the arene occupies three
facial coordination sites and the phosphine, chloride and
carbene complete the coordination sphere. In 1b and 2b
the chelate phosphinopropylarene ligand occupies four
coordination sites and the chloride and carbene com-
plete the coordination sphere. The quality of the crystals
of 2b was poor, but was sufficient to establish the atom
Me3C6H2ꢁ
/
5-CH2CH2CH2P(C6H5)2)RuCl2]
complex
with excess (trimethylsilyl)acetylene and phenylacety-
lene, respectively (Scheme 2).
A characteristic red to orange color change was
observed during the progress of each reaction. The
isolated complexes are orange air-stable solids, which
are slightly soluble in halocarbons and soluble in
acetone and alcohols. The spectroscopic properties of
these carbenes are similar to those of previously
reported analogous (methoxy)ꢁalkylcarbenes [9]. In
/
1
their H NMR spectra, the complexes display the three
typical multiplets for the vinyl protons of the DPVP
ligand in the region 6.8ꢁ5.1 ppm. Due to the presence of
/
Scheme 1. Synthesis of (methoxy)ꢁalkylcarbenes.
/

14
K.Y. Ghebreyessus, J.H. Nelson / Inorganica Chimica Acta 350 (2003) 12ꢁ24
/
Scheme 2. Synthesis of tethered (methoy)ꢁ/alkylcarbenes.
Table 1
Crystallographic data for 1a, 1b, 2b and 3b
Compound
Empirical formula
Mw
1a
C
1b
2b
3b
C40H41ClF6OP2Ru
850.19
27H33ClF6OP2Ru
C28H35ClF6OP2Ru
770.92
monoclinic
P21/c
C33H37ClF6OP2Ru
762.09
monoclinic
P21/c
685.99
orthorhombic
P/bca
17.183(5)
17.013(4)
19.777(7)
8
Crystal system
Space group
monoclinic
P21/c
˚
a (A)
15.6430(14)
8.7983(12)
24.654(3)
4
12.486(3)
27.713(8)
9.482(6)
4
14.6805(16)
14.8197(10)
18.3785(15)
4
˚
b (A)
˚
c (A)
Z
a (8)
b (8)
g (8)
Volume (A )
rcalc
90
90
90
108.191(4)
90
90
100.53(3)
90
90
110.070(10)
90
90
3
˚
5781(3)
1.576
6196
3223.6(6)
1.588
7254
3226(2)
1.569
5344
3755.6(6)
1.504
8076
Reflections collected
Independent reflections
R1(F) a,b
wR2(F2) a,b
5088
5680
4208
6612
0.0717
0.0619
0.1483
1.043
0.0618
0.1089
1.024
0.1074
0.2394
1.034
0.1231
1.003
Goodness-of-fit
a
The data were refined by the method of full-matrix least-squares on F2, with the final R indices having I ꢀ
2s(I).
/
b
R(F)ꢀ
/
a(jFojꢂ
/
jFcj)2/a(jFoj); wR2(F2)ꢀ
/
[a w(jFo2jꢂ
/
jFc2j)2/a wjFc2j]1/2
.
connectivity. The Ruꢁ
/
C(25) distances, 1.96, 1.98 and
those reported previously [9] for similar complexes. In
these complexes, the C(25)ꢁO(1) bond lengths are
˚
1.99 A for 1a, 1b and 2b, respectively, are comparable to
/
2
˚
shorter than the 1.4 A expected for C(sp )ꢁ
/O single
Table 2
Selected bond distances (A) and bond angles (8) for 1a and 1bꢁ
bonds and suggest some CꢀO double bond character.
/
˚
/3b
However, all the angles at the carbene carbon atoms in
1a, 1b and 2b approach 1208, which indicate sp2
hybridization. In agreement with the observation made
in our previous report, the bond lengths and angles for
the non-chelated 1a are nearly identical to those in the
chelated carbenes 1b and 2b [10]. The common metrical
parameters for 1a, 1b and 2b are very similar. The
1a
1b
2b
3b
Ruꢁ
Ruꢁ
Ruꢁ
/
P
2.345(2)
2.3975(19) 2.406(2)
2.3162(19) 2.324(5)
2.319(2)
2.39492)
1.972(8)
1.323(9)
/Cl
2.398(5)
1.994(19)
1.27(2)
/C(25)
1.963(7)
1.303(8)
1.985(7)
1.292(8)
C(25)ꢁ
Ruꢁ(C1ꢁ
PꢁRuꢁCl
C(25)ꢁRuꢁ
C(25)ꢁRuꢁ
/
O
a
/
/
C6)
2.2945(8)
86.79(7)
83.7(2)
2.275(7)
88.39(7)
87.4(2)
2.2793(17)
89.07(19)
85.2(5)
2.2802(8)
92.44(7)
85.3(2)
/
/
complexes display dihedral angles (u) in the range 71.4ꢁ
79.78: where the dihedral angle is defined as the angle
between the [C(arene centroid)ꢁRuꢁC(carbene)] and
[(CH2R)ꢁC(carbene)ꢁOCH3] planes.
/
/
/P
/
/
Cl
91.7(2)
90.8(2)
92.5(6)
90.6(2)
/
/
a
(C1ꢁ
/
C6) denotes the average RuꢁC distances.
/
/
/

K.Y. Ghebreyessus, J.H. Nelson / Inorganica Chimica Acta 350 (2003) 12ꢁ
/24
15
compared to the tetramethyl benzene ligand expected
to bring about an increase in this angle (Table 2).
The electrochemistry of the complexes has been
studied by cyclic voltammetry. For each of the com-
plexes, a reversible Ru(II)/Ru(III) couple was observed.
The oxidation potentials for each of these carbene
complexes (Table 3) is higher than that of their
phosphine precursors [10]. This reflects the expected
decrease in electron density at the ruthenium(II) center
for these cationic carbene complexes compared to the
neutral phosphine precursors.
Attempts to prepare analogous (methoxy)ꢁ
bene complexes from the tethered precursors [(h6-
areneꢁCH2CH2CH2P(C6H5)2)RuCl2] (areneꢀC6H5, p-
/
alkylcar-
/
/
MeC6H4, p-Me2CHC6H4, 3,5-Me2C6H3) under similar
conditions were unsuccessful (Scheme 3). In each case,
decomposition products were recovered.
It was previously shown that the stability of the [(h6-
arene)Ru(PR3)Ru(Cl) (carbene)]ꢃ complexes largely
depends on the sterric influence of ancillary ligands
around the ruthenium center [11]. We have recently
observed that the tethered phosphinopropylarene com-
plexes are structurally and electronically similar to their
non-tethered phosphine precursors [10]. Thus, chelation
of these less bulky and weaker electron donor arene
ligands did not help to form stable carbene complexes.
Fig. 1. Structural drawing of the cation of 1a showing the atom
numbering scheme (20% probability ellipsoids). Hydrogen atoms are
omitted for clarity.
2.2. Synthesis of (methoxy)ꢁ
/
alkenylcarbene (3b)
The reaction of [(h6-1,2,4-Me3C6H2ꢁ
/5-CH2CH2-
CH2P(C6H5)2)RuCl2] with excess 1,1-diphenylpropargyl
alcohol and 1 equiv. of NaPF6 in methanolꢁdichlor-
omethane solution gave the (methoxy)ꢁalkenylcarbene
/
/
complex 3b, as an orange powder (EEq. (2)). The
complex results from nucleophilic attack of CH3OH
on the a-carbon of allenylidene intermediates [1].
Fig. 2. Structural drawing of the cation of 1b showing the atom
numbering scheme (30% probability ellipsoids). Hydrogen atoms are
omitted for clarity.
ð2Þ
1
The IR and H, 31P{1H} and 13C{1H} NMR spectra
confirm the formation of complex 3b.The IR spectrum
(Nujol) exhibits, in addition to the absorption for the
hexafluorophosphate anion (840 cmꢂ1) a strong n(Cꢀ
/
C) vibration at 1976 cmꢂ1. The Rꢁ
not detected in its 13C{1H} NMR spectrum.
/
Ca carbon for 3b was
These values are greater than those reported [9] for the
analogous hexamethyl benzene (methoxy)ꢁalkylcar-
/
The electrochemistry of the vinylcarebene complex
was also studied by cyclic votammetry. The cyclic
voltammogram shows a reversible Ru(II)/Ru(III) redox
benes. These results may indicate a subtle interplay of
electronic and sterric effects in the solid state structures
with the much bulkier hexamethyl benzene ligand
couple. Similar to the (methoxy)ꢁalkylcarbene com-
/

16
K.Y. Ghebreyessus, J.H. Nelson / Inorganica Chimica Acta 350 (2003) 12ꢁ24
/
Table 3
13C{1H} and cyclic voltammetric data for 1aꢁ
/
3a and 1bꢁ
/3b
Compound
d
13C{1H} for Ruꢀ
/C (ppm)
2J(PC) (Hz)
E1/2 Ru(II)/Ru(III) (V) a
DEp (mV)
1a
2a
1b
2b
3b
327.22
321.90
19.2
19.1
0.90
1.0
232
153
153
115
120
b
0.85
0.95
0.90
327.04
b
19.2
a
Measured in CH2Cl2 solution at a glassy carbon working electrode, 0.1 M tetrabutylammonium hexafluorophosphate as supporting electrolyte.
All potentials are vs. Fc/Fcꢃ. Scan rate 100 mV sꢂ1
.
b
RuꢀCa was not detected.
/
plexes the oxidation potential of 3b is higher than its
phosphine precursor [10].
X-ray crystallographic analyses confirmed the struc-
˚
C(25) distance 1.972(8) A and
ture of 3b. The Ruꢁ
/
˚
C(25)ꢁ
reported for the analogous complex [(C6Me6)(PMe3)-
(Cl)RuꢀC(OMe)CHꢀCPh2]PF6 [1a]. The C(27)ꢁC(28)
bond length (1.321(10) A) is consistent with a Cꢀ
/O (1.323(9) A) distances are similar to those
/
/
/
˚
/C
double bond for 3b. A view of the molecular structure is
shown in Fig. 3. Crystallographic data are given in
Table 1 and selected bond distances and angles in Table
2. The common metrical parameters for 2b and 3b are
very similar.
2.3. Catalytic hydration of phenylacetylene
We have conducted preliminary catalytic tests of the
tethered [(h6-areneꢁ
/
CH2CH2CH2P(C6H5)2)RuCl2] and
the non-tethered analogues for the hydration of pheny-
lacetylene (Eq (3)).
Fig. 3. Structural drawing of the cation of 3b showing the atom
numbering scheme (30% probability ellipsoids). Hydrogen atoms are
omitted for clarity.
present in the commercial 95% ethanol. Adding an
additional 1.5 equiv. of water with everything else being
the same has no effect on the yield or product selectivity.
ð3Þ
Acetophenone was isolated in 45ꢁ
phenylacetylene Table 4. The 1H NMR spectra and
GCꢁMS of the extracted product confirm the produc-
/
66% yield based on
Phenyacetylene was heated at reflux in 95% ethanol in
the presence of 2.5 mol% of the catalyst for 24 h.
Complete conversion was achieved by using the water
/
Scheme 3. Attempted synthesis of (methoxy)ꢁalkylcarbenes.
/

K.Y. Ghebreyessus, J.H. Nelson / Inorganica Chimica Acta 350 (2003) 12ꢁ
/24
17
Table 4
(h6-arene)Ru(II) complex-catalyzed hydration of phenylacetylene
Entry
Catalyst
Mol%
Time (h)
Percentage yield
1
2
[(h6-MeC6H5)Ru(DPVP)Cl2]
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
24
24
24
24
24
24
24
24
24
24
53
48
52
45
55
50
61
56
61
65
[(h6-C6H5ꢁ
/
(CH2)3ꢁ
[(h6-p-Me2C6H4)Ru(DPVP)Cl2]
[(h6-p-MeC6H4ꢁ
(CH2)3ꢁP(C6H5)2)RuCl2]
[(h6-p-MeC6H4CHMe2)Ru(DPVP)Cl2]
[(h6-p-Me2CHC6H4ꢁ
(CH2)3ꢁP(C6H5)2)RuCl2]
[(h6-1,3,5-Me3C6H3)Ru(DPVP)Cl2]
[(h6-1,3-Me2C6H3ꢁ
5-(CH2)3ꢁP(C6H5)2)RuCl2]
[(h6-1,2,4,5-Me4C6H2)Ru(DPVP)Cl2]
[(h6-1,2,4-Me3C6H2ꢁ
5-(CH2)3ꢁP(C6H5)2)RuCl2]
/
P(C6H5)2)RuCl2]
3
4
/
/
5
6
/
/
7
8
/
/
9
10
/
/
The reaction temperature was 80 8C.
tion of acetophenone. Blank runs in the absence of the
catalysts gave no acetophenone.
isocyanide complexes 1cꢁ
(Scheme 4).
The related tethered complexes 1d and 2d were also
synthesized from [(h6-areneꢁ
CH2CH2CH2P(C6H5)2)-
RuCl2] (areneꢀ,3,5-Me2C6H3 1d, p-Me2CHC6H4 2d)
/
4c as yellowꢁ
/
orange solids
Previously, Tokunaga and Wakatsuki [12a] reported
similar catalytic reactions using [(h6-C6H6)Ru(PR3)Cl2]
/
(PR3ꢀPPh2(C6F5) and P(3-C6H4SO3Na)3 for the anti-
/
/
Markovnikov hydration of terminal alkynes. In their
study they selectively produced the desired aldehydes.
More recently [12b], they conducted a detailed mechan-
istic study involving both experimental results and
theoretical calculations for the catalytic anti-Markovni-
kov hydration of terminal alkynes. On the basis of their
experimental and theoretical findings they propose a
mechanism which involves Ru(IV)-hydride-vinylidene
intermediates with the first key step being protonation
of an h2-coordinated alkyne. In our system, the addition
of water across the terminal alkyne seems to follow
Markovnikov’s rule to produce acetophenone exclu-
sively. In their mechanistic studies Tokunaga et al. [12b]
suggested that the initial step for the production of
ketones is similar to the formation of aldehydes. The
regioselection process seems to originate in the proto-
nation step. Thus, if a proton is attached to the terminal
carbon, it results in the formation of ketones. Con-
versely, if a proton is attached to the Ca carbon, it
results in the formation of aldehydes. Involvement of
both steric and electronic factors was also suggested in
the regioselection process. However, unlike the forma-
tion of aldehydes the intermediate following the proto-
nation step in the production of ketones remains to be
established. Our preliminary results show that the
reactivity of both the tethered and non-tethered com-
plexes is comparable at 80 8C.
by employing the same methodology (Scheme 5). The
complexes have been characterized by IR and 1H,
13C{1H} and 31P{1H} spectroscopy (details are given
in the Section 3) and elemental analyses.
The complexes exhibit a characteristic IR absorption
2168 cmꢂ1 for 1cꢁ
in the range 2144ꢁ
/
/
4c and 2153ꢁ
/
2170
C) for
cmꢂ1 (Table 7) for 1d and 2d attributable to n(Nꢂ
/
the bound isocyanide ligand. These absorptions are at
slightly higher energy than that of the uncoordinated
phenyisocyanide ligand (2126 cmꢂ1). The 1H NMR
spectra of 1cꢁ
in the range 6.92ꢁ
/
4c show the three characteristic multiplets
5.27 ppm for the DPVP ligand. The
/
Scheme 4. Synthesis of phenyl isocyanide complexes.
2.4. Synthesis of isocyanide ruthenium(II) complexes
(1cꢁ
/
4c, 1d and 2d)
Reaction of [(h6-arene)Ru(DPVP)Cl2] (areneꢀ
/1,3,5-
Me3C6H3 1c, p-MeC6H4ꢁCHMe2 2c, 1,2,4,5- Me4C6H2
3c and Me6C6 4c) with excess phenyl isocyanide and
NaPF6 in methanolꢁdichloromethane solution gave
/
/
Scheme 5. Synthesis of tethered phenyl isocyanide complexes.

18
K.Y. Ghebreyessus, J.H. Nelson / Inorganica Chimica Acta 350 (2003) 12ꢁ24
/
spectra of 1d and 2d contain three multiplets for the
three-methylene protons. Notably, the 13C NMR signals
of the coordinated phenylisocyanide were found in the
center are not of sufficient strength to render the
isocyanide carbon electrophilic in these complexes.
This is also consistent (vide infra) with the X-ray
structural data for the ruthenium(II) phenylisocyanide
complexes. Thus, the coordinated phenyl isocyanide
ligand is not sufficiently electrophilic to be susceptible
to nucleophilic attack. Therefore, the [(h6-arene)R-
u(DPVP)(CNPh)Cl]PF6 complexes are not good pre-
cursors for the synthesis of aminocarbenes.
The molecular structures of 4c and 1d were deter-
mined by X-ray crystallography (Figs. 4 and 5, respec-
tively). Crystallographic data for 4c and 1d are shown in
Table 5, while selected bond distances and bond angles
are given in Table 6. The molecular structure of each of
the ruthenium(II) isocyanide complexes consists of a
pseudo-octahedral geometry around the ruthenium
center. The ruthenium is surrounded by one chloride,
one phenylisocyanide, one phosphine and one arene
region 155ꢁ
/
147 ppm for 1cꢁ
/
4c, 1d and 2d which is 18ꢁ
/
26 ppm downfield of the uncoordinated phenylisocya-
nide (129 ppm). In contrast to the formation of
RuCl2(CNR)4 derivatives from [Ru(C6H6)2]2, [8] no
displacement of the arene ligand was observed in the
synthesis of 1cꢁ
synthesize analogous phenylisocyanide complexes from
[(h6-arene)Ru(DPVP)Cl2]
(areneꢀMeC6H5, p-
/4c. On the other hand, attempts to
/
MeC6H4Me) under similar conditions failed. Arene
ligand displacement was observed for both of these
precursors.
The goal of the work described in the second part of
this report is to attempt the synthesis of aminocarbenes
from the coordinated phenyl isocyanide ligand. To
explore whether this idea works or not, a mixture of
the isocyanide precursors (1cꢁ
a fivefold excess of benzylamine or ethanolꢁ
/
4c) and/or 1d and 2d with
methanol
/
was stirred in boiling acetonitrile solution for 24 h
(Scheme 6).
However, the starting material or decomposition
products were recovered in each case. All the phenyl
isocyanide complexes display a positive Dnꢀ
C)coordꢂn(NꢂC)free value in the range 41ꢁ
17 cmꢂ1
This reflects a relatively weak back-donation (d0p*) to
/
n(Nꢂ
/
/
/
/
.
/
the coordinated phenylisocyanide ligand. Previous Stu-
dies have indicated that nucleophilic attack at the
coordinated isocyanides should occur when there is a
positive Dn ]
compounds was near to or much less than this. The
values of the IR NꢂCstretch of the coordinated
/
40 cmꢂ1 [6,7]. The value obtained for our
/
phenylisocyanide suggest that, the ruthenium(II) center
in these cationic complexes is a relatively poor p-donor.
Apparently, the s-donation of the isocyanide and/or the
weak p-back donation from the cationic ruthenium(II)
Fig. 4. Structural drawing of the cation of 4c showing the atom
numbering scheme (30% probability ellipsoids). Hydrogen atoms are
omitted for clarity.
Scheme 6. Attempted synthesis of aminocarbenes.

K.Y. Ghebreyessus, J.H. Nelson / Inorganica Chimica Acta 350 (2003) 12ꢁ
/24
19
Table 6
Selected bond distances (A) and bond angles (8) for 4c and 1d
˚
4c
1d
Ruꢁ
Ruꢁ
Ruꢁ
Ruꢁ
NꢁC(13)
/
P
2.337(5)
2.394(5)
2.3229(12)
2.394(12)
1.934(4)
/Cl
/C(13)
1.867((17)
2.297(17))
1.204(18)
a
/
(C1ꢁ
/C6)
2.2675(4)
1.157(5)
/
PꢁRuꢁCl
C(24)ꢁRuꢁ
C(24)ꢁRuꢁ
C(24)ꢁNꢁC(25)
/
/
85.27(16)
84.10(5)
87.5(5)
88.23(4)
87.17(13)
85.97(13)
173.6(5)
/
/
P
/
/Cl
/
/
172.5(18)
a
(C1ꢁ
/
C6) denotes the average RuꢁC distances.
/
Cꢁ
/
Nꢁ
/Ph fragment is essentially linear in these struc-
tures.
Fig. 5. Structural drawing of the cation of 1d showing the atom
numbering scheme (30% probability ellipsoids). Hydrogen atoms are
omitted for clarity.
The electrochemical behavior of these phenyl isocya-
nide complexes has been studied by cyclic voltammetry
(Table 7). The cyclic voltammograms of the complexes
Table 5
Crystallographic data for 4c and 1d
1cꢁ3c, 1d and 2d showed irreversible Ru(II)/Ru(III)
oxidations, whereas that of complex 4c appears to be
reversible. Oxidation of 4c occurs at a lower potential
/
Compound
Empirical formula
Mw
4c 1d
C33H36ClF6NP2Ru C30H30ClF6NP2Ru
730.57
than those of 1cꢁ3c as expected because hexamethy-
/
benzene is a better p-donor than the other arene ligands
and its complexes are more easily oxidized.
717.01
triclinic
Crystal system
Space group
˚
triclinic
¯
¯
P1
P/1
/
a (A)
˚
9.5470(16)
17.570(2)
21.126(4)
4 c
9.4136(13)
9.9486(9)
17.6077(11)
2
2.5. Conclusions
b (A)
˚
c (A)
Z
Methoxyꢁ
/
alkyl and methoxyꢁalkenyl ruthenium(II)
/
a (8)
b (8)
g (8)
Volume (A )
rcalc
77.707(19)
76.964(16)
74.251(14)
3279.0(9)
1.538
102.435(6)
92.545(7)
110.747(8)
1492.7(3)
1.595
carbene complexes were synthesized from [(h6-1,2,4,5-
Me4C6H2)Ru(DPVP)Cl2] and the tethered [(h6-1,2,4-
3
˚
Me3 C6H2ꢁ
/
5-CH2CH2CH2P(C6H5)2)RuCl2] precursors,
1-alkyne and 1,1-diphenylpropargyl alcohol. They are
orange air stable solids at ambient temperature.
Reflections collected
Independent reflections
R1(F) a,b
10 366
8508
6266
5220
In addition, isocyanide complexes were synthesized
from the same precursors and phenylisocyanide. Com-
0.0922
0.0755
0.977
0.0429
0.1012
1.024
wR2(F2) a,b
plexes 1cꢁ3c, 1d and 2d show irreversible Ru(II)/Ru(III)
/
Goodness-of-fit
redox couples, whereas 4c shows a reversible oxidation.
Attempts to synthesize aminocarbenes from the coordi-
nated isocyanide were unsuccessful. The complexes [(h6-
a
The data were refined by the method of full-matrix least-squares
on F2, with the final R indices having I ꢀ
/
2s(I).
wR2(F2)ꢀ
b
R(F)ꢀ
/
a(jFojꢂ
/
jFcj)2/a(jFoj);
/
[a w(jFo2jꢂ
/
jFc2j)2/
a wjFc2j]1/2
.
Two inequiv. cations in the asymmetric unit.
c
Table 7
IR data and Ru(II)/Ru(III) potentials for 1cꢁ4c, 1d and 2d
/
˚
C distances (1.867(17) A for 4c and
ligand. The Ruꢁ
/
b
Compound n(Nꢂ
/
C)
)
Dn
E1/2 Ru(II)/Ru(III)
(V) c
DEp
(mV)
˚
(cmꢂ1
a
1.934(4) A for 1d) are shorter than the expected Ruꢁ
/
C
˚
single bond length 2.122(7) A [9,13]. These values are
d
d
d
1c
2c
3c
4c
1d
2d
2156
2168
2156
2144
2153
2170
29
41
29
17
26
44
1.56
1.53
1.52
1.07
1.58
1.59
˚
within the range (1.894(3)ꢁ
/
1.903(4) A) for Ruꢀ
/
C bond
of the recently reported [(p-cymene)(Pr3iP)(Cl)Ruꢀ
/
Cꢀ
/
˚
Cꢀ
/
CPh2]ꢃ [3a]. The Nꢁ
for 4c and 1.156 A for 1d are slightly longer than the
/
C bond distances of 1.205 A
138
d
˚
d
˚
average value 1.14 A for an Nꢁ
/C triple bond [14]. These
a
b
c
data indicate that there is only modest carbene character
in these ruthenium(II) phenylisocyanide complexes with
IR Nujol mull.
2126 cmꢂ1
.
Metrabutylammonium hexafluorophosphate as supporting elec-
Dnꢀ
/
[n(Nꢂ
/
C)coordꢂ
/
n(Nꢂ
/
C)free]; n(Nꢂ
/
C)freeꢀ
/
little back-donation. The C(24)ꢁ
/
N(3)ꢁ
/
C(25) bond an-
trolyte. All potentials are vs. Fc/Fcꢃ. Scan rate 100 mV sꢂ1
.
d
gles 172.6(4) for 4c and 173.7(5) for 1d indicate that the
Epa only, irreversible.

20
K.Y. Ghebreyessus, J.H. Nelson / Inorganica Chimica Acta 350 (2003) 12ꢁ24
/
arene)Ru (DPVP)Cl2] and [(h6-areneꢁ
(C6H5)2)RuCl2] are good catalysts for the Markovnikov
hydration of phenylacetylene to produce acetophenone.
/
CH2CH2CH2P-
3.2.1.1. Compound 1a. M.p. 135ꢁ137 8C (68% yield).
/
1H NMR (500 MHz, CDCl3, 25 8C), d 7.40ꢁ
/
7.61 (m,
23.5 Hz, J(HaHb)ꢀ
12.0 Hz, 1H, Ha), 6.17 (dd,
38.5 Hz, 3J(HaHc)ꢀ
12.0 Hz 1H, Hc), 5.49
(s, 2H, CH arene), 5.37 (dd, 3J(PH)ꢀ
20.0 Hz,
3J(HaHb)ꢀ
18.5 Hz, 1H, Hb), 4.23 (s, 3H, OCH3),
3. Experimental
2
3
10H, PPh2), 6.59 (ddd, J(PH)ꢀ
18.5 Hz, 3J(HaHc)ꢀ
3J(PH)ꢀ
/
/
3.1. Reagents and physical measurements
/
/
/
All chemicals were reagent grade and were used as
received or synthesized as described below. Dichloro-
methane and acetonitrile were dried over CaH2 and
distilled immediately before use. The precursors [(h6-
/
/
2.94 (s, 3H, 3CH3), 19.2 (s, 6H, CH3 arene), 1.88 (s,
6H, CH3 arene). 13C{1H} NMR (125.7 MHz, CDCl3,
arene)Ru(DPVP)Cl2] [10], [(h6-areneꢁ
/
CH2CH2CH2P-
2
25 8C), d 327.22 (d, J(PC)ꢀ
/
19.23 Hz, Ruꢀ
/
C), 137.87
9.4 Hz,
2
2
(C6H5)2)RuCl2] [10] and phenylisocyanide [15] were
synthesized by literature procedures. Elemental analyses
were performed by Galbraith Laboratories, Knoxville,
TN. Melting points (m.p.) were obtained using a Mel-
Temp apparatus and are uncorrected. NMR spectra
were recorded on a Varian Unity plus-500 FT NMR
(d, J(PC)ꢀ
/
10.1 Hz, Co), 132.69 (d, J(PC)ꢀ
Co), 131.87 (d, J(PC)ꢀ
/
1
/
45.63 Hz, Ci), 131.69 (s, Cb),
1
131.40 (s, Cp), 131.10 (s, Cp), 130.91 (d, J(PC)ꢀ
/35.1
1
Hz, Ca), 129.18 (d, J(PC)ꢀ
/
40.40 Hz, Ci), 128.63 (d,
3J(PC)ꢀ
/
10.4 Hz, Cm), 109.43 (s, Cq arene), 106.11 (s,
Cq arene), 100.34 (s, CH arene), 66.96 (s, OCH3), 41.19
(s CH3), 16.72 (s, CH3 arene), 16.33 (s, CH3 arene).
31P{1H} NMR (202.3 MHz, CDCl3, 25 8C), d 30.70 (s,
1
spectrometer operating at 500 MHz for H, 125.7 MHz
for 13C and 202.3 MHz for 31P. Proton and carbon
chemical shifts are relative to internal Me4Si, while
phosphorus chemical shifts are relative to external 85%
H3PO4 (aq.) with positive values being downfield of the
respective reference. FT IR Spectra were recorded on a
1p, DPVP), ꢂ
/
145.0 (septet, 1p, 1J(PF)ꢀ
731.0 Hz,
/
PF6ꢂ). Anal. Calc. for C27H33ClF6OP2Ru (1a): C,
47.23; H, 4.81; Cl, 5.18. Found: C, 47.14; H, 4.79; Cl,
5.09%.
PerkinꢁElmer Spectrum BX Spectrometer as Nujol
/
mulls on NaCl windows. Cyclic voltammograms were
recorded at 25 8C in freshly distilled CH2Cl2 containing
0.1 M tetrabutylammonium hexafluorophosphate using
a BAS CV50-W voltammetric analyzer. A three-elec-
trode system was used. The working electrode was a
glassy carbon disk; the auxiliary electrode was a
platinum electrode and the reference electrode was an
aq. Agꢃ/AgCl electrode separated from the cell by a
Luggin capillary. The Fc/Fcꢃ couple occurred at 506
mV [16] under the same conditions.
3.2.1.2. Compound 2a. M.p. 138ꢁ140 8C (76% yield).
/
1H NMR (500 MHz, CDCl3, 25 8C), d 7.22ꢁ
15H, PPh2, and Ph), 6.79 (ddd, 2J(PH)ꢀ
23.5 Hz,
3J(HaHb)ꢀ18.5 Hz, 3J(HaHc)ꢀ
12.0 Hz, 1H, Ha),
6.20 (dd, 3J(PH)ꢀ40.0 Hz, 3J(HaHc)ꢀ
12.0 Hz 1H,
19.5 Hz, J(HaHb)ꢀ18.5 Hz,
1H, Hb), 5.19 (s, 2H, CH arene), 5.05 (d, J(Hx?Hy?)ꢀ
12.5 Hz, 1H, Hx?), 4.46 (s, 3H, OCH3), 3.78 (d,
2J(Hx?Hy?)ꢀ
12.5 Hz, 1H, Hy?), 1.75 (s, 12H, CH3
arene). 13C{1H} NMR (125.7 MHz, CDCl3, 25 8C), d
321.90 (d, 2J(PC)ꢀ
19.1 Hz, RuꢀC), 134.28 (d,
/7.51 (m,
/
/
/
/
/
3
3
3.2. Synthesis
Hc), 5.37 (dd, J(PH)ꢀ
/
/
2
/
3.2.1. Preparations of 1a, 2a, 1b, and 2b
A solution containing 0.50 mmol of [(h6-arene)R-
/
u(DPVP)Cl2] in 20 ml 1:1 methanolꢁdichloromethane
/
was purged with nitrogen. To the red solution 1.5 mmol
of (trimethylsilyl)acetylene (1a) or 1.5 mmol of pheny-
lacetylene (2a) and 1 equiv. of NaPF6 were added and
the mixture was stirred for 4 h. Then the solvent was
evaporated to dryness. The solid residue was dissolved
in 10 ml of dichloromethane and filtered to remove
NaCl. The volume of the filtrate was reduced to 5 ml by
rotary evaporation and layered with ether. The products
were separated by gravity filtration to give 1a and 2a as
orange powders. Compounds 1b and 2b were synthe-
sized employing the same methodology, from the [(h6-
/
/
2J(PC)ꢀ
2J(PC)ꢀ
/
10.1 Hz, Co), 133.59 (s, Cp), 132.71 (d,
/
9.2 Hz, Co), 131.93 (s, Ci Ph), 131.79 (s, Cb),
131.26 (s, Co Ph), 131.17 (d, 1J(PC)ꢀ
/
35.2 Hz, Ca),
47.6 Hz, Ci), 130.86 (s, Cm Ph),
110.09 (s, Cq arene), 107.54 (s, Cq arene), 101.0 (d,
J(PC)ꢀ3.7 Hz, CH arene), 66.26 (s, OCH3), 54.91 (s
130.86 (d, 1J(PC)ꢀ
/
/
CH2), 16.91 (s, CH3 arene), 16.64 (s, CH3 arene).
31P{1H} NMR (202.3 MHz, CDCl3, 25 8C), d 31.0 (s,
1p, DPVP), ꢂ
/
145.0 (septet, 1p, 1J(PF)ꢀ
731.0 Hz,
/
PF6ꢂ). Anal. Calc. for C33H37ClF6OP2Ru (2a): C,
51.96; H, 4.86; Cl, 4.66. Found: C, 51.86; H, 4.83; Cl,
4.56%.
1,2,4-Me4C6H2ꢁ
/5-CH2CH2CH2P(C6H5)2)RuCl2] pre-
cursor.

K.Y. Ghebreyessus, J.H. Nelson / Inorganica Chimica Acta 350 (2003) 12ꢁ
/24
21
3.2.1.3. Compound 1b. M.p. 139ꢁ
/
142 8C (49% yield).
6.3 Hz, C1), 101.38 (s, C8), 100.29 (s, C2), 93.03 (s, C5),
69.05 (s, OCH3), 56.49 (s CH2), 26.05 (s, Cc), 21.98 (d,
2J(PC)ꢀ
(s, C9) 16.84 (d, J(PC)ꢀ
(202.3 MHz, acetone-d6, 25 8C), d 27.71 (s, 1p, DPVP),
145.0 (septet, 1p, 1J(PF)ꢀ731.0 Hz, PF6ꢂ). Anal.
/
35.1 Hz, Ca), 20.88 (s, Cb), 17.44 (s, C8), 17.30
/
1.1 Hz, C7). 31P{1H} NMR
ꢂ
/
/
Calc. for C33H37ClF6OP2Ru (2b): C, 51.96; H, 4.86; Cl,
4.66. Found: C, 51.86; H, 4.83; Cl, 4.56%.
1H NMR (500 MHz, acetone-d6, 25 8C), d 7.63 (m,
4H, Ho), 7.43 (m, 6H, Hm,p), 6.26 (s, 1H, CH arene),
6.22 (s, 1H, CH arene), 4.09 (s, 3H, OCH3), 2.77
3.2.2. Preparation of 3b
The reaction was carried out as above, using the
corresponding [(h6-1,2,4-Me4C6H2ꢁ
(C6H5)2)RuCl2] complex.
/5-(CH2CH2CH2P-
(apparent td, 2J(HaHa?)ꢀ
2J(PH)ꢀ
(apparent dq, 2J(HbHb?)ꢀ
3J(HaHb)ꢀ
7.0 Hz, 1H, Hb), 2.48 (apparent qd,
2J(HcHc?)ꢀ14.5 Hz, 3J(Hc?Hb)ꢀ3
J(HcHb)ꢀ4.0 Hz,
1H, Hc), 2.30 (m, 2H, Hb,c?), 2.29 (s, 3H, H8), 2.24 (s,
3H, H9), 1.98 (s, 3H, H7), 1.62 (dddd, 2J(PH)ꢀ
28.0 Hz,
13.0 Hz, J(HaHb?)ꢀ
4.0 Hz, 1H, Ha?). 13C{1H} NMR (125.7 MHz, acetone-
d6, 25 8C), d 136.29 (d, 1J(PC)ꢀ
51.2 Hz, Ci), 135.21 (d,
2J(PC)ꢀ10.6 Hz, Co), 134.71 (d, 1J(PC)ꢀ
47.4 Hz, Ci),
/
15.5 Hz, 3J(HaHb)ꢀ
7.0 Hz, 1H, Ha), 2.76 (s, 3H, 3CH3), 2.68
15.0 Hz, 3J(PH)ꢀ
/
/
/
/
/
/
/
/
3.2.2.1. Compound 3b. M.p. 174ꢁ
/
176 8C (52% yield).
/
3
3
2J(HaHa?)ꢀ
/
14.0 Hz, J(HaHb)ꢀ
/
/
/
/
/
2
1
132.54 (d, J(PC)ꢀ
45.63 Hz, Ci), 131.88 (d, J(PC)ꢀ
(d, 4J(PC)ꢀ
2.6 Hz, Cp), 129.28 (s, Cm), 129.14 (d,
3J(PC)ꢀ
10.7 Hz, Cm), 114.98 (s, C6), 112.20 (d,
J(PC)ꢀ9.3 Hz, C4), 104.43 (d, J(PC)ꢀ6.0 Hz C1),
99.91 (s, C3), 98.65 (s, C2), 94.32 (s, C5), 66.74 (s,
/
8.4 Hz, Co), 131.87 (d, J(PC)ꢀ
/
4
/
2.4 Hz, Cp), 131.22
1H NMR (500 MHz, acetone-d6, 25 8C), d 7.83 (m,
4H, Ho, PPh2), 7.54 (m, 6H, Hm,p, PPh2), 7.32 (m, 6H,
/
/
/
/
H
m,p, CPh2), 7.04 (m, 4H, Ho, CPh2), 6.08 (s, 1H, Hꢁ
C), 5.07 (bs, 2H, H2,5), 4.38 (s, 3H, OCH3), 3.00
(apparent td, 2J(HaHa?)ꢀ14.5 Hz, 3J(HaHb)ꢀ
2J(PH)ꢀ
5.5 Hz, 1H, Ha), 2.71 (apparent dq,
2J(HbHb?)ꢀ15.5 Hz, 3J(HaHb)ꢀ3
J(HbHc)ꢀ4.0 Hz,
/
Cꢀ
/
3
OCH3), 42.17 (s, CH3), 26.13 (d, J(PC)ꢀ
22.45 (d, J(PC)ꢀ
C8), 17.04 (s, C9) 17.04 (d, J(PC)ꢀ
/
1.1 Hz, Cc),
34.2 Hz Ca), 21.16 (s, Cb), 17.16 (s,
1.3 Hz, C7). 31P{1H}
/
/
2
/
/
/
/
/
/
NMR (202.3 MHz, acetone-d6, 25 8C), d 29.89 (s, 1p,
1Hb), 2.56 (m, 2H, Hc,c?), 2.42 (m, 1H, Hb?), 2.15 (s,
3H, H8), 2.09 (s, 3H, H9), 2.05 (s, 3H, H7), 1.81 (m, 1H,
Ha?). 13C{1H} NMR (125.7 MHz, acetone-d6, 25 8C), d
1
DPVP), ꢂ
/
145.0 (septet, 1p, J(PF)ꢀ
731.0 Hz, PF6ꢂ).
Anal. Calc. for C27H33ClF6OP2Ru (1b): C, 47.23; H,
4.81; Cl, 5.18. Found: C, 47.14; H, 4.79; Cl, 5.09%.
/
141.71 (s, Cd), 140.17 (s, Ce), 135.66 (s, Ci, CPh2), 135.26
2
(s, Ci, CPh2), 135.15 (d, J(PC)ꢀ
/
10.2 Hz, Co, PPh2),
3.2.1.4. Compound 2b. M.p. 141ꢁ143 8C (55% yield).
/
133.62 (d, 1J(PC)ꢀ
2J(PC)ꢀ8.2 Hz, Co, PPh2), 132.51 (d, 4J(PC)ꢀ
Hz, Cp, PPh2), 131.75 (d, J(PC)ꢀ
/48.0 Hz, Ci, PPh2), 132.87 (d,
1H NMR (500 MHz, acetone-d6, 25 8C), d 7.70 (m,
4H, Ho, PPh2), 7.50 (m, 6H, Hm,p? PPh2), 7.32 (m, 4H,
/
/2.5
4
/
2.6 Hz, Cp, PPh2),
H
m,p? Ph), 7.10 (m, 1H, Ho, Ph), 6.30 (s, 1H, H2), 5.40 (s,
1H, H5), 4.81 (d, 2J(Hx?Hy?)ꢀ
13.0 Hz, 1H, Hx?), 4.38 (s,
3H, OCH3), 4.17 (d, J(Hx?Hy?)ꢀ13.0 Hz, 1H, Hy?),
131.34 (s, Co, CPh2), 130.60 (s, C0, CPh2), 129.98 (s, Cm,
PPh2), 129.88 (d, 1J(PC)ꢀ
52.7 Hz, Ci, PPh2), 129.77 (s,
Co, CPh2), 129.59 (s, Cm, CPh2), 129.58 (d, 3J(PC)ꢀ
9.9
Hz, Cm, PPh2), 129 51 (s, Cm, CPh2), 129.43 (s, Cp,
CPh2), 129.21 (s, Cp, CPh2), 103.96 (d, J(PC)ꢀ5.9 Hz,
C4), 103.83 (s, C3), 102.48 (s, C6), 102.06 (s, C1), 80.32 (s,
/
/
2
/
/
2.84 (m, 1H, Ha), 2.69 (m, 1H, Hb), 2.61 (s, 3H, H8), 2.50
(m, 2H, Hc,c?), 2.36 (m, 1H, Hb?), 2.26 (s, 3H, H9), 1.96
3.5 Hz, 3H, H7), 1.73 (m, 1H, Ha?). 13C{1H}
/
(d, J(PH)ꢀ
/
NMR (125.7 MHz, acetone-d6, 25 8C), d 327.04 (d,
4
1
2J(PC)ꢀ
Ci), 135.24 (d, 2J(PC)ꢀ
133.70 (d, 1J(PC)ꢀ48.0 Hz, Ci), 132.75 (d, 2J(PC)ꢀ
Hz, Co), 132.24 (d, 4J(PC)ꢀ
2.6 Hz, Cp), 131.60 (d,
4J(PC)ꢀ
2.6 Hz, Cp), 130.96 (s, Co, Ph), 130.01 (s, Cm,
Ph), 129.43 (d, 3J(PC)ꢀ
9.9 Hz, Cm), 129.34 (d,
3J(PC)ꢀ
10.7 Hz, Cm), 128.37 (s, Cp, Ph), 114.82 (d,
J(PC)ꢀ8.4 Hz, C4), 114.08 (s, C6), 104.17 (d, J(PC)ꢀ
/
19.2 Hz, Ruꢀ
/
C), 136.58 (d, J(PC)ꢀ
10.7 Hz, Co), 133.79 (s, Ci, Ph),
8.4
/
50.5 Hz,
C2), 74.98 (s, C5), 70.32 (s, OCH3), 25.96 (d, J(PC)ꢀ
/
2
1.6 Hz, Cc), 20.97 (d, J(PC)ꢀ
/
40.98 Hz Ca), 20.51 (s,
/
Cb), 17.44 (s, C8), 17.34 (s, C9), 17.07 (d, J(PC)ꢀ
/
1.3
Hz, C7). 31P{1H} NMR (202.3 MHz, acetone-d6, 25 8C),
/
/
/
1
d 24.97 (s, 1p, DPVP), ꢂ
/
145.0 (septet, 1p, J(PF)ꢀ
/
/
731.0 Hz, PF6ꢂ). Anal. Calc. for C40H41ClF6OP2Ru
(3b): C, 56.46; H, 4.82; Cl, 4.18. Found: C, 56.36; H,
4.78; Cl, 4.08%.
/
/
/
/

22
K.Y. Ghebreyessus, J.H. Nelson / Inorganica Chimica Acta 350 (2003) 12ꢁ
/24
1
3.2.3. General procedure for (h6-arene)Ru(II)-catalyzed
hydration of phenylacetylene
(septet, 1p, J(PF)ꢀ
/
731.0 Hz, PF6ꢂ). Anal. Calc. for
C30H30ClNF6P2Ru (1c): C, 50.21; H, 4.18; Cl, 4.95.
Found: C, 50.15; H, 4.15; Cl, 4.86%.
A solution containing 2.5 mol.% of the catalyst and
2.0 ml of phenylacetylene in 10 ml of ethanol was heated
at reflux for 24 h. Then the solution was cooled to room
temperature (r.t.) and a minimum amount of ether was
added to the resulting suspension and filtered. The
filtrate was vacuum distilled by using a distillation
3.2.4.2. Compound 2c. M.p. 192ꢁ
1H NMR (500 MHz, CDCl3, 25 8C), d 7.48ꢁ
10H, PPh2), 7.34 (m, 3H, Hm,p? CNPh), 7.17 (m, 2H, Ho,
/
194 8C (75% yield).
/7.84 (m,
2
3
CNPh), 6.92 (ddd, J(PH)ꢀ
/
23.5 Hz, J(HaHb)ꢀ
/
18.5
12.0 Hz, 1H, Ha), 6.17 (dd, J(PH)ꢀ
20.0 Hz, 3J(HaHc)ꢀ
12.0 Hz 1H, Hc), 6.02 (d,
3J(HH)ꢀ
6.0 Hz, 1H, CH arene), 5.82 (d, J(HH)ꢀ
7.0 Hz, 2H, CH arene), 5.77 (d, J(HH)ꢀ
3
3
apparatus. The acetophenone was collected at 70ꢁ
73 8C/0.3ꢁ0.5 mmHg (48ꢁ66 isolated % yield) and
analyzed by 1H NMR spectroscopy and GCꢁ
MS
/
Hz, J(HaHc)ꢀ
/
/
/
/
/
3
/
/
/
3
spectrometry.
/
6.0 Hz, 1H,
3
3
CH arene), 5.27 (ddd, J(PH)ꢀ
/
20.0 Hz, J(HaHb)ꢀ
/
18.5 Hz, 3J(HbHc)ꢀ
/1.5 Hz, 1H, Hb), 2.72 (septet,
3.2.4. Synthesis of phenylisocyanide complexes
3J(HH)ꢀ
3J(HH)ꢀ
/
7.0 Hz, 1H, CH), 1.98 (s, 3H, CH3), 1.22 (d,
7.0 Hz, 6H, 2CH3). 13C{1H} NMR (125.7
A solution containing 0.50 mmol of [(h6-arene)R-
/
u(DPVP)Cl2] (areneꢀ
CHMe2 2c, 1,2,4,5-Me4C6H2 3c and Me6C6 4c) in 30
ml 1:1 methanolꢁdichloromethane was purged with
/1,3,5-Me3C6H3 1c, p-MeC6H4-
2
MHz, CDCl3, 25 8C), d 148.83 (d, J(PC)ꢀ
/
30.2 Hz,
CNPh), 134.0 (d, 2J(PC)ꢀ
2J(PC)ꢀ10.1 Hz, Co), 132.81 (d, 3J(PC)ꢀ
132.25 (d, 1J(PC)ꢀ56.9 Hz, Ci), 131.67 (d, 4J(PC)ꢀ
/
10.0 Hz, Co), 133.87 (d,
/
/
/9.4 Hz, Cm),
nitrogen. To the red solution was added 2.4 mmol of
phenylisocyanide and 1 equiv. of NaPF6. After stirring
for 24 h at r.t., the solvent was removed by rotary
evaporation. The solid residue was dissolved in 15 ml of
dichloromethane and filtered to remove NaCl. The
volume of the filtrate was reduced to 5 ml by rotary
evaporation and layered with ether. The products were
/
/2.4
1
Hz, Cp), 131.11 (d, J(PC)ꢀ
Cb), 129.74 (d, 4J(PC)ꢀ
CNPh), 129.0 (d, 1J(PC)ꢀ
3J(PC)ꢀ
9.6 Hz, Cm), 126.89 (s, Co, CNPh), 126.50 (s,
Cm, CNPh), 126.36 (s, Ci, CNPh), 120.06 (d, J(PC)ꢀ
/
50.11 Hz, Ca), 130.17 (s,
/2.0 Hz, Cp), 129.61 (s, Cp,
/46.38 Hz, Ci), 128.04 (d,
/
/
3.1 Hz, Cq arene), 111.57 (s, CH arene), 99.11 (s, CH
arene), 98.03 (s, Cq arene), 95.67 (s, CH arene), 93.09 (s,
CH arene), 31.57 (s, CH), 22.82 (s, CH3), 18.43 (s, CH3).
31P{1H} NMR (202.3 MHz, CDCl3, 25 8C), d 26.90 (s,
separated by gravity filtration to give 1cꢁ
powders. Compounds 1d and 2d were synthesized
employing the same methodology, from [(h6-areneꢁ
5-
CH2CH2CH2P(C6H5)2)RuCl2] (areneꢀ1,3,5-Me2C6H3
1d, p-C6H4CHMe2 2d) precursors.
/
4c as yellow
/
/
1p, DPVP), ꢂ
/
145.0 (septet, 1p, 1J(PF)ꢀ
731.2 Hz,
/
PF6ꢂ). Anal. Calc. for C31H32ClNF6P2Ru (2c): C,
50.92; H, 4.38; Cl, 4.86. Found: C, 50.87; H, 4.32; Cl,
4.76%.
3.2.4.3. Compound 3c. M.p. 162ꢁ
1H NMR (500 MHz, CDCl3, 25 8C), d 7.64 (m, 4Ho,
PPh2), 7.49ꢁ7.59 (m, 6H, Hm,p? PPh2), 7.41 (m, 3H,
Hm,p? CNPh), 7.23 (m, 2H, Ho, CNPh), 6.87 (ddd,
2J(PH)ꢀ24.5 Hz, 3J(HaHb)ꢀ18.5 Hz, 3J(HaHc)ꢀ
12.0
Hz, 1H, Ha), 6.10 (dd, J(PH)ꢀ41.0 Hz, J(HbHc)ꢀ
12.0 Hz 1H, Hb), 5.75 (s, 2H, CH arene), 5.37 (dd,
/
165 8C (78% yield).
3.2.4.1. Compound 1c. M.p. 196ꢁ
1H NMR (500 MHz, CDCl3, 25 8C), d 7.45ꢁ
10H, PPh2), 7.36 (m, 3H, Hm,p? CNPh), 7.25 (m, 2H, Ho,
/
198 8C (70% yield).
/
/761 (m,
/
/
/
2
3
3
3
CNPh), 6.79 (ddd, J(PH)ꢀ
/
23.5 Hz, J(HaHb)ꢀ
/
18.2
12.0 Hz, 1H, Ha), 6.17 (dd, J(PH)ꢀ
41.5 Hz, J(HaHc)ꢀ12.0 Hz 1H, Hc), 5.55 (s, 3H, CH
/
/
3
3
Hz, J(HaHc)ꢀ
/
/
3
/
3J(PH)ꢀ
/
20.5 Hz, 3J(HaHc)ꢀ
18.5 Hz, 1H, Hc), 1.97 (s,
/
arene), 5.49 (dd, 3J(PH)ꢀ
/
20.7 Hz, 3J(HaHb)ꢀ
/
18.2 Hz,
1H, Hb), 2.19 (s, 9H, 3CH3). 13C{1H} NMR (125.7
12H, 4CH3). 13C{1H} NMR (125.7 MHz, CDCl3,
2
25 8C), d 151.70 (d, J(PC)ꢀ
/
28.9 Hz, CNPh), 133.88
2
2
2
MHz, CDCl3, 25 8C), d 150.40 (d, J(PC)ꢀ
/29.40 Hz,
(d, J(PC)ꢀ
/
10.3 Hz, Co), 132.81 (d, J(PC)ꢀ9.6 Hz,
Co), 132.15 (s, Cb), 131.67 (s, Cp), 131.58 (d, J(PC)ꢀ
50.2 Hz, Ci), 130.30 (d, J(PC)ꢀ
/
1
CNPh), 134.27 (d, 2J(PC)ꢀ
2J(PC)ꢀ
9.4 Hz, Co), 132.27 (s, Cb), 132.10 (d,
4J(PC)ꢀ
2.6 Hz, Cp), 131.62 (d, J(PC)ꢀ2.5 Hz, Cp),
/
10.2 Hz, Co), 132.84 (d,
/
1
/
/50.3 Hz, Ci), 130.2 (s,
4
/
/
Cp), 129.80 (s, Co, CNPh), 129.35 (s, Cp, CNPh), 129.23
3
1
1
131.41 (d, J(PC)ꢀ
/
51.2 Hz, Ca), 130.39 (d, J(PC)ꢀ
/
(d, J(PC)ꢀ
Cm), 127.98 (d, J(PH)ꢀ
/
10.7 Hz, Cm), 129.02 (d, 3J(PC)ꢀ
/
10.7 Hz,
1
53.9 Hz, Ci), 130.05 (s, Cp, CNPh), 129.60 (s, Cm,
/
53.3 Hz, Ca), 127.35 (s, Ci,
3
CNPh), 129.22 (d, J(PC)ꢀ
3J(PC)ꢀ10.7 Hz, Cm), 127.35 (d, 1J(PC)ꢀ
127.21 (s, Ci, CNPh), 126.46 (s, Co, CNPh), 117.58 (d,
J(PC)ꢀ2.0 Hz, Cq arene), 92.30 (d, J(PC)ꢀ2.8 Hz,
CH arene), 19.25 (s, CH3 arene). 31P{1H} NMR (202.3
MHz, CDCl3, 25 8C), d 34.69 (s, 1p, DPVP), ꢂ145.0
/
10.8 Hz, Cm), 128.90 (d,
CNPh), 126.31 (s, Cm, CNPh), 108.85 (s, Cq arene),
100.85 (s, CH arene), 16.77 (s, CH3). 31P{1H} NMR
(202.3 MHz, CDCl3, 25 8C), d 34.30 (s, 1p, DPVP),
/
/53.5 Hz, Ci),
/
/
ꢂ
/
145.0 (septet, 1p, 1J(PF)ꢀ731.4 Hz, PF6ꢂ). Anal.
/
Calc. for C31H32ClNF6P2Ru (3c): C, 50.92; H, 4.38; Cl,
4.86. Found: C, 50.85; H, 4.30; Cl, 4.77%.
/

K.Y. Ghebreyessus, J.H. Nelson / Inorganica Chimica Acta 350 (2003) 12ꢁ
/24
23
3.2.4.4. Compound 4c. M.p. 207ꢁ
1H NMR (500 MHz, acetone-d6, 25 8C), d 7.43ꢁ
(m, 10H, PPh2), 7.40 (m, 3H, Hm,p? CNPh), 7.20 (m, 2H,
/
210 8C (82% yield).
1p, 1J(PF)ꢀ731.0 Hz, PF6ꢂ). Anal. Calc. for
C30H30ClNF6P2Ru (1d): C, 50.21; H, 4.18; Cl, 4.95.
Found: C, 50.15; H, 4.15; Cl, 4.86%.
/
/
7.60
2
3
Ho, CNPh), 6.89 (ddd, J(PH)ꢀ
18.0 Hz, 3J(HaHc)ꢀ
12.0 Hz, 1H, Ha), 6.04 (dd,
3J(PH)ꢀ40.5 Hz, 3J(HbHc)ꢀ
12.0 Hz 1H, Hb), 5.47
(ddd, 3J(PH)ꢀ20.0 Hz, 3J(HaHc)ꢀ
18.0 Hz,
0.5 Hz,
/
24.0 Hz, J(HaHb)ꢀ
/
/
3.2.4.6. Compound 2d. M.p. 195ꢁ197 8C (55% yield).
/
/
/
/
/
3J(HbHc)ꢀ
/
1.0 Hz 1H, Hc), 1.98 (d, J(PH)ꢀ
/
18H, 6CH3). 13C{1H} NMR (125.7 MHz, acetone-d6,
2
25 8C), d 155.06 (d, J(PC)ꢀ
/
27.9 Hz, CNPh), 134.72
2
2
(d, J(PC)ꢀ
/
9.8 Hz, Co), 134.39 (d, J(PC)ꢀ9.8 Hz,
/
Co), 132.84 (s, Cb), 132.54 (s, Cp), 132.24 (s, Cp), 130.77
(s, Co, CNPh), 130.59 (s, Cp, CNPh), 129.75 (d,
3J(PC)ꢀ
/
9.9 Hz, Cm), 129.48 (d, 3J(PC)ꢀ
10.3 Hz,
/
Cm), 129.39 (s, Cm, CNPh), 129.18 (d, 1J(PC)ꢀ
/
52.7
1H NMR (500 MHz, CDCl3, 25 8C), d 7.70 (m, 4H,
Ho), 7.49 (m, 6H, Hm,p), 7.20 (m, 3H, Hf,g), 7.04 (m, 2H,
1
Hz, Ci), 129.0(d, J(PC)ꢀ
/
51.9 Hz, Ca), 128.44 (s, Ci,
CNPh), 109.15 (d, J(PC)ꢀ
/
2.6 Hz, Cq arene), 16.21 (d,
He), 6.57 (d, 3J(HH)ꢀ
5.0 Hz, 1H, H3), 6.15 (AB,
/
J(PC)ꢀ1.0 Hz, CH3 arene).
/
3
3J(HH)ꢀ
2H, H5), 3.04 (septet, 3J(HH)ꢀ
2J(PH)ꢀ
15.5 Hz, 1H, Hc), 2.64 (m, 1H, Hb), 2.52 (m,
2H, Hb?,c?), 2.29 (m, 2J(PH)ꢀ
/
6.5 Hz, 2H, H2,6), 5.85 (d, J(HH)ꢀ
/5.0 Hz,
31P{1H} NMR (202.3 MHz, acetone-d6, 25 8C), d
/
7.0 Hz, 1H, H7), 2.91 (d,
1
34.24 (s, 1p, DPVP), ꢂ
/
145.0 (septet, 1p, J(PF)ꢀ
/731
/
Hz, PF6ꢂ). Anal. Calc. for C33H36ClNF6P2Ru (4c): C,
52.20; H, 4.75; Cl, 4.68. Found: C, 52.15; H, 4.67; Cl,
4.56%.
/
33.5 Hz, 1H, Ha), 1.69 (m,
7.5 Hz, 3H, H7), 1.33 (d,
6.5 Hz, 3H, H8). 13C{1H} NMR (125.7 MHz,
3
1H, Ha?), 1.44 (d, J(PH)ꢀ
/
3J(PH)ꢀ
/
2
CDCl3, 25 8C), d 147.40 (d, J(PC)ꢀ
/
23.0 Hz, CNPh),
1
2
134.33 (d, J(PC)ꢀ
/
10.1 Hz, Co), 132.14 (d, J(PC)ꢀ
/
3.2.4.5. Compound 1d. M.p.ꢀ200 dec. (45% yield).
/
55.6 Hz, Ci), 132.07 (d, 2J(PC)ꢀ
/
8.5 Hz, Co), 131.73 (d,
4J(PC)ꢀ
130.62 (d, 4J(PC)ꢀ
Ce), 128.81 (d, 3J(PC)ꢀ
3J(PC)ꢀ
10.8 Hz, Cm), 127.84 (s, Cf), 126.77 (s, Cd),
124.48 (d, J(PC)ꢀ8.3 Hz, C1), 102.95 (s, C2), 97.59 (s,
C4), 97.17 (s, C6), 96.22 (s, C3), 88.37 (s, C5), 31.12 (s,
/
2.3 Hz, Cp), 130.67 (d, J(PC)ꢀ
2.6 Hz, Cp), 129.74 (s, Cg), 129.03 (s,
10.7 Hz, Cm), 128.50 (d,
/
50.7 Hz, Ci),
1
/
/
/
/
1
C7), 29.80 (s, Cc), 23.87 (s, C8), 23.54 (d, J(PC)ꢀ
Hz, Ca), 20.00 (s, C9), 19.84 (s, Cb). 31P{1H} NMR
(202.3 MHz, CDCl3, 25 8C), d 29.82 (s, 1p, ꢁPPh2),
145.0 (septet, 1p, 1J(PF)ꢀ731.3 Hz, PF6ꢂ). Anal.
/35.3
/
1H NMR (500 MHz, acetone, 25 8C), d 7.68 (m, 4H,
Ho), 7.55 (m, 2H, Hp), 7.45 (m, 1H, Hg), 7.41 (m, 2H,
Hf), 7.36 (m, 4H, Hm), 6.95 (m, 2H, He) 6.49 (s, 1H, H4),
6.36 (s, 1H, H2), 5.63 (s, 1H, H6), 3.18 (apparent dq,
ꢂ
/
/
Calc. for C31H32ClNF6P2Ru (2d): C, 50.92; H, 4.38; Cl,
4.86. Found: C, 50.87; H, 4.32; Cl, 4.76%.
2J(Hbb?)ꢀ
/
14.0 Hz, 3J(Hab)ꢀ3
/
J(Hbc)ꢀ3.5 Hz, 1H,
/
Hb?), 2.82 (m, 1H, Ha?), 2.65 (s, 3H, H7), 2.48 (s, 3H,
H8), 2.33 (m, 3H, Hb,c,c?), 1.68 (m, 1H, Ha?). 13C{1H}
NMR (125.7 MHz, acetone, 25 8C), d 152.91 (d,
3.2.5. X-ray data collection and processing
Crystals of the complexes, obtained from CH2Cl2ꢁ
/
hexane for 1a, CH2Cl2ꢁether for 1b, 4c solvent mixtures
/
2J(PC)ꢀ
/
28.9 Hz, CNPh), 135.58 (d, 2J(PC)ꢀ
/
10.4
54.2 Hz, Ci), 132.80 (d,
and by slow evaporation of acetone for 2b, 3b, and 1d
were mounted on glass fibers, coated with epoxy, and
placed on a Siemens P4 diffractometer. Intensity data
were taken in the v-mode at 298 K with Mo Ka
graphite monochromated radiation (lꢀ
1
Hz, Co), 135.19 (d, J(PC)ꢀ
/
2J(PC)ꢀ
/
8.3 Hz, Co), 132.38 (d, J(PC)ꢀ
/
2.6 Hz, Cp),
2.8 Hz, Cp), 131.69 (d, J(PC)ꢀ
4
4
1
131.75 (d, J(PC)ꢀ
51.3 Hz, Ci), 130.93 (s, Cg), 130.42 (s, Cf), 129.56 (d,
3J(PC)ꢀ10.3 Hz, Cm), 129.40 (d, 3J(PC)ꢀ
10.9 Hz,
Cm), 128.14 (s, Cd), 127.29 (d, 5J(PC)ꢀ
0.6 Hz, Ce),
120.09 (d, J(PC)ꢀ5.0 Hz, C1), 104.61 (d, J(PC)ꢀ1.6
Hz, C7), 101.53 (d, J(PC)ꢀ9.9 Hz, C8), 94.36 (s, C4),
84.73 (s, C2,6), 30.64 (d, J(PC)ꢀ1.6 Hz, Cc), 24.35 (d,
/
/
˚
0.71073 A).
/
/
/
Three check reflections monitored every 100 reflections
/
showed random (B2%) variation during the data
/
/
/
collections. The data were corrected for Lp and absorp-
tion using an empirical model derived from azimuthal
data collections. Scattering factors and corrections for
anomalous dispersion were taken from a standard
source [17]. Calculations were performed with the Sie-
mens SHELXTL plus version 5.10 software package on a
/
3
/
1J(PC)ꢀ
20.23 (s, C7) 18.74 (s, C8). 31P{1H} NMR (202.3 MHz,
acetone, 25 8C), d 30.87 (s, 1p, ꢁPPh2), ꢂ145.0 (septet,
/
34.7 Hz, Ca), 20.79 (d, J(PC)ꢀ1.4 Hz, Cb),
/
2
/
/

24
K.Y. Ghebreyessus, J.H. Nelson / Inorganica Chimica Acta 350 (2003) 12ꢁ24
/
[2] (a) C. Bruneau, P.H. Dixneuf, Acc. Chem. Res. 32 (1999) 311;
(b) C. Slugovc, K. Mereiter, R. Schmid, K. Kirchner, Organo-
metallics 18 (1999) 1011.
personal computer. The structures were solved by
Patterson methods. Anisotropic thermal parameters
were assigned to all non-hydrogen atoms. Hydrogen
[3] (a) A. Furstner, M. Liebl, C.W. Lehmann, M. Picquet, R. Kunz,
¨
C. Bruneu, D. Touchard, P.H. Dixneuf, Chem. Eur. J. 6 (2000)
1847;
atoms were refined at calculated positions with a riding
˚
H vector was fixed at 0.96 A.
model in which the Cꢁ
/
(b) A. Furstner, Angew. Chem. Int. Ed. 39 (2000) 3012.
¨
[4] (a) F.-W. Lee, M.-Y. Choi, K.-K. Cheung, C.-M. Che, J.
Organomet. Chem. 595 (2000) 114.;
Compound 1b crystallized as a dichloromethane solvate.
(b) R. Dussel, D. Pilette, P.H. Dixneuf, W.P. Fehlhammer,
Organometallics 10 (1991) 3287;
4. Supplementary material
(c) H.A. Mayer, W.C. Kaska, Chem. Rev. 94 (1994) 1239.
[5] (a) K.M. Pietrusiewicz, M. Zablocka, Chem. Rev. 94 (1994) 1375;
(b) E. Singlton, H.E. Oosthuizen, Adv. Organomet. Chem. 22
(1983) 209.
Tables of crystal data and structure refinement,
atomic coordinates, isotropic and anisotropic displace-
ment parameters, bond lengths and angles, and hydro-
gen coordinates for 1a, 1b, 2b, 3b, 4c and 1d. X-ray
crystallographic data, in CIF format, are also available
from the authors.
[6] (a) A.J.L. Pombeiro, M.F. Guedes da Silva, R.A. Michelin,
Coord. Chem. Rev. 218 (2001) 43;
(b) A.J.L. Pombeiro, M.F. Guedes da Silva, R.A. Michelin,
Coord. Chem. Rev. 218 (2001) 75;
(c) M. Tamm, F.E. Hahn, Coord. Chem. Rev. 182 (1999) 175.
[7] B. Crociani, in: P.S. Braterman (Ed.), Reactions of Coordinated
Ligands, Plenum Press, New York, 1986, p. 553.
Acknowledgements
[8] (a) F. Faraone, V. Marsala, Inorg. Chim. Acta 27 (1978) L109;
(b) Y. Yamamoto, H. Nakamura, J.-F. Ma, J. Organomet. Chem.
640 (2001) 10.
This research was supported by an award from the
Research Corporation and by the donors of the
Petroleum Research Fund Administered by the Amer-
ican Chemical Society. We are grateful for this support.
[9] H.D. Hansen, J.H. Nelson, Organometallics 19 (2000) 4740.
[10] K.Y. Ghebreyessus, J.H. Nelson, Organometallics 19 (2000) 3387.
[11] D. Devanne, P.H. Dixneuf, J. Organomet. Chem. 390 (1990) 371.
[12] (a) M. Tokunaga, Y. Wakatsuki, Angew. Chem. Int. Ed. 37
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